Before you proceed for the installation you should know the difference between OpenERP Apps vs Module. If you are going to install modules that is available locally, make sure your are on latest version of that modules. Its better to work with the OpenERP Apps store that always deliver latest in terms of versions along with the bugfix and improvements.

On successfully installed Indian Localization l10n_in_base you will get a page under Settings → Configuration → Indian Localization. You can choose depending what you want to install as a feature from the Indian localization.